Caveolin 1 (Cav1) is the gene product of the Cav1 locus. Cav1 is a member of the caveolin family of proteins along with Cav2 and Cav3 as well as some invertebrate caveolins. Cav1 is a phosphoprotein with a structural role in the formation of caveolae, organelles with multiple but controversial assigned functions. Loss of Cav1 results in severe dislipidemia both in mouse and humans. It also leads to a cardiovascular phenotype with dilative cardiomyopathy and pulmonary hypertension. In addition, loss of Cav1 protein results in a type II diabetes syndrome with hyperglyceridemia, hyperinsulinemia and decreased tolerance to glucose. Caveolin 1 is involved in multiple signal transduction pathways. It is believed to be a tumor suppressor, as well as an angiogenesis inhibitor. Caveolin 1 is involved in mechanical flow sensing as well as in inflammation and permeability.